Manufacture of rubber compounds.



LOUIS COLLARDON, O1? W'ESl-f lllttOB/EWIGH,

MANUFACTURE OF RUBBER; CClIillPQ'UNDS,

lilo Drawing",

To all whom it may concern Be it known that l, Louis CoLLAnooN, acitizen of Agentina, residing at 73 Bratt street, West Bromwich, in thecounty of li arwickshire, England, have invented new and usefulimprovements in the Manufacture of Rubber Compounds, of Which thefollowing; is a specification.

The invention relates to the production of compounds consisting ofcellulose Xanthate or other cellulose esters and rubber or rubber-likesubstances Several processes for combining rubber and cellulosecompounds and also obtaining a vulcanized product have been proposed. Ithas also been proposed to incorporate resin with rubber and cellulosecompounds.

My invention dillt'ers from previous inventions by reason. of the factthat the cellulose esters aroused in a pasty condition whereas in thecase of previous inventions viscose in solution has been employed ornitrated cellulose, neither of Which are suitable for the purposes of myinvention.

According; to my invention I produce materials or compositionsconsisting of cellulose esters and a small quantity of rubber orrubber-like subsaances suilicient to produce a coherent mass,a rawmaterial which can be readily mixed With rubber or other substancesnecessary for vulcanization and moreover gives a thoroughly uniform product. Furthermore as I use newly made cellulose xanthate in plastic formnot in solution and certain kinds of caoutchouc which are particularlysuitable for the production of a homogeneous composition the productionof this raw material can be attained all more quickly than is possiblein the case ot' the product resulting from the above cited process.

Before describing; methods of production or manufacture which ll mayadopt T will enumerate some of the rubber or rubber" like substanceswhich may be used. The caoutchoucs which may be employed are thoseobtained from the West llt'rican coast. such as Conakry, Sierra Leone,Nigger Flake, flora, l'iiberia lumps, Angola niggers, root rubber or thelike, or soft rubbers such as those obtained from Borneo. Sumatra,Baniermassin or the Malay dtates, or the rubber obtained from Dicfiopasor Diode se's pol mbibe and many other similar trees. llllexican rubber,sucl' as guayule, which is very rich in resin, also be used TheSpecification of Letters Patent.

Patentetll June 2, Mil i,

Application filed January so, 191% Serial No. earnest ruhber-likecoagulate known to the natives as brea, obtained from the latexes ofcertain large trees growing in the Amazon r ver territory, Peru,Bolivia, Columbia and :Venezuela which have not. been botanioallvidentified, is particularly suitable for the purpose of my invention asit will, especially while in a soft condition, readily combine withviscose and other cellulose esters. In addition to the above may bementioned the coagulates of a great variety of caoutchouclike trees, theso-called bastardos, which are often mixed with real. caoutchouc,guttapercha or balata, as well as the latexes of other trees, such asRims om'n'icifera, the juice of the unripe fruits of the kaki tree(Dz'oepyro Kaine L.) and. many other trees. especially those growing inChina and [la pan, such for instance as AZmu-ites cordutm Dryamieravcordata, E'lrcocoaca vernz'cia. All these natural products and manyothers will be found to be useful for the purpose of my invention, oneof the chief features (it which is the use of resinous caoutchoucs,which render unnecessary the use of oily and fatty substances and thelike, which only destroy or decrease the valuable properties ofcaoutchouc. Finally newly made synthetic caoutchouc, While still in asoft condition, or the polymerized hydrocarbons of the divinyl group areparticularly suitable for the purpose of my invention since thesechemical products readily combine with viscose or other cellulose estersand the mixture can be vulcanized with or Without the addition of othercaoutchoucs. Synthetic c-aoutchouc. and the same holds good with regardto the polymerized hydrocarbons of the divinyl group, possesses theimportant advantage that only a small quantity need be added to thecellulose xantha-te or sulfohydrocellulose to produce a uniform product.an important advantage from the technical point oi. View.

When cellulose xanthate is used the improved compounds may bemanufactured in the following" manner: First of all alkali-eel llili'lrLis made which contains less alkali than is customarily used in the caseof common Xanthate, as the presence of smaller amount of undissolvedfiber of cellulose Will not render the alkali-cellulose unsuitable forthe purpose of my invention. suitable quantity oi" carbon bisultid isadded to the all alicellulose as soon. as the latter has ripened, andalter the reaction. due to such addition has taken place the cellulosexanthate is worked between either cold or heated rollers until such timeas a plastic body is produced. Soft or resinous rubber, either syntheticor natural, or soft regenerated rubber is then added in small quantitiesto this plasticbody. The total amount of rubber which is added is merelyjust sufficient to produce a. coherent substance which will not fractureor tear, when mixed or rolled or washed. The above named product is thenformed, by passing it between slightly heated rollers, into thin sheets.These sheets which are homogeneous, as can be seen by holding them up tothe light, still con tain a slight quantity of moisture and alkali whichmust be removed to make the cellulose product perfectly insoluble. Thismay be effected byeither drying them in an ordinary oven or in a vacuumapparatus or in steaming apparatus such as that used in the manufactureof textile goods. A few minutes are sufficient to render the xanthateinsoluble, so that the impurities and the alkali can be removed bywashing. After washing the material is centrifuged, again dried andsheeted. The drying must be carefully carried out so as to avoid failureduring vulcanization, which would occur if the material were not fullydried. The product will then be ready to be used for making goods, t.6., to be mixed with definite quantities of sulfur, variouschemicals,filling material and rubber, murao, balata or other rubber orrubber-like substances, according to requirements. The addition ofsulfo-hydrocellulose, which is absolutely insoluble in any known solventand which can be readily prepared by the addition of chlorid of sulfurto newly made cellulose xanthate, will change the nature of the productto a certain degree and enable other original materials to be closelyimitated. This means that technical improvements of a very importantnature can be achieved, especially in the manufacture of ebonite,artificial leather, linoleum and the like. Further the addition ofsulfur, zinc oxid or zinc sulfid to the raw product, that is to say tothe mixture of rubber and cellulose ester, is advantageous as it willgreatly assist vulcanization and give the product better di-electricqualities.

According to another method of production suitable cellulose material istreated with a more or less concentrated solution of hydrochloric orsulfuric acid and after the cellulose material has become converted intoa finely divided pulp chlorid of sulfur is added. An absolutelyinsoluble compound results. and this compound is thoroughly washed, thendried and finally reduced to a fine powder. Viscose (solution) may alsobe treated with sulfur chlorid and after being washed and "dried may bereduced to 9.

fine powder. Either of the fine powders so produced would beincorporated with rubber, guttapereha, balata, murac or other rubber orrubber-like substances.

The following are examples of relative proportions of the substances,which I have found to give satisfactory results Example I: 10 kilos ofundissolved cellulose xanthate in plastic form. 14 kilos of guayulerubber. 1 kilo of a soft resinous rubber. such as paste or flake. 1 kiloof zinc oxid or zinc sulfid? 200 grams of sulfur. 4-5 kilos of fillingmaterial.

The above are mixed thoroughly, rolled into thin sheets, dried, thensteamed and washed, and finally thoroughly dried, molded and vulcanized.

Example II: 20 kilos of cellulose xanthate in plastic form. 14.- kilosof a soft resinous rubber, such as paste or flake, or other rubber orrubber-like substance. 1 kilo of zinc sulfid. 1 kilo of zinc oxid. 1kilo of sulfur.

The mixture is treated in the same way as No. I.

Example III: 10 kilos of cellulose xanthate in plastic form. 12 kilos ofsynthetic rubber. 4: kilos of recovered rubber. 1 kilo of sulfur. 5kilos of filling material.

The mixture is treated in the same Way as 95 No. I.

Example IV: 20 kilos of cellulose xanthate in. plastic form. 4 kilos ofrubber resin. 4 kilos of reclaimed soft rubber. 1 kilo of sulfur.

The mixture is treated in the same way asv No. I.

Example V: 10 kilos of dry sulfo-hydrocellulose. 5 kilos of fillingmaterial. 2-41 kilos of soft rubber. kilo of sulfur. I

The mixture is treated in the same way as No. I.

Having now described my invention what I have invented and desire tosecure by Letiters Patent of the United States is as fol- 0 ows:

1. A process for the production of water-- proof compounds, consistingin treating cellulose with a reagent adapted to form a solutiontherewith, treating the solution in order to form a cellulose compoundsubstantially free from water, mixing the compound with a small quantityof rubber to produce a coherent mass, and with a vulcanizing agent, andvulcanizing the product.

2. A process for the production of waterproof compounds, consisting inpreparing cellulose 'xanthate solution, treating the same in order toexpel free moisture and to reduce the product to a plastic form, mixingthe plastic product with sufficient rubber to produce a coherent mass,adding a vulcaniz ing agent to the mass, and vulcanizing the product.

3. A process for the production of waterroeonee proof compounds,consisting in preparing cellulose xentharte solution, treeting the somein order to expel free moisture end'to reduce the product to a plasticform, mixing the plastic product with su'flicient rubber to produce acoherent mass, passing the mixture through heated rollers to formsheets, further heating the product in order to 'finelly dry the sameend to rencler the cellure lose compound insoluble, weehing the product,centritugmg and drying the same, end finally vulcenizin the roduct.

In testimony W ereo l have signed my name' to this specification in thepresence of two subscribing Witnesses.

LOUIS COLLARDUN.

'Witnesses:

ARTHUR F. Emma, H. l). JAMesoN.

